The theatrical section of the Lluïsos d'Horta is the amateur group L'Auca and every year at Christmas they have the task of staging the Pastorets (Shepherds' Play) with the help of the association's other members. In fact, Els Pastorets and the theatrical performances that are staged in honour of Sant Lluís, their patron saint, are unique occasions because all the centre's members are involved as actors or stagehands, whether or not they belong to the theatre group.

The version they put on is a free adaptation of the nativity story entitled Dimonis i pastorets (Devils and Shepherds), written by the group and based on the texts of Josep M. Folch i Torres, Frederic Soler, aka Pitarra, and Ramon Pàmies. As well as this, the children in the theatre group's acting nursery put on their own show: Plomes, banyetes i pastorets (Feathers, Little Horns and Shepherds), which is also a free version of the traditional shepherds' nativity plays.

Lluïsos d'Horta was founded in 1866 as a Catholic centre, the Centre Moral Instructiu. Its activities are linked to its different sections: cinema, hiking, folklore, photography, handicrafts, table tennis, children's entertainment and theatre. They also arrange musical performances, film screenings, exhibitions and workshops.